Kitchen device with safety interlock

Abstract

A household mixer-blender includes a housing 1 with a reception seat 3. The housing contains an electric motor unit 4 whose output shaft projects into the seat 3. A removable bowl 7 includes a base 9 with a sidewall 10 and is urged to interlock in operating condition on the seat. A central part 12 of the base 9 carries a rotating tool 13 integral with shaft 14 passing through the electric motor unit 4 and base 9. A first safety device includes at least one retractably mounted blocking member 17 is mounted in the reception seat 3. The blocking member is designed to have a first inoperative position in which it is retracted by an actuating member 22 integral with bowl base 23 when the bowl 7 is properly fixed to the base 9, as well as an operative position in which the blocking member is no longer controlled by the actuating member 22 when the bowl 7 is not on the base 9 or is not properly fixed to such base.

I claim:  
     
       1. Kitchen appliance comprising a housing ( 1 ) having on an upper portion ( 2 ) a reception seat ( 3 ) and enclosing an electric motor unit ( 4 ) so that an output shaft ( 5 ) of the electric motor unit projects into the seat ( 3 ), a removable bowl ( 7 ) having a removable bottom ( 8 ) comprising a base ( 9 ) having a sidewall ( 10 ) of a shape complementary to the shape of the reception seat ( 3 ) to be seated in operation on said seat, a central region ( 12 ) of the base carrying a rotatable tool ( 13 ) secured to a shaft ( 14 ) passing through said base ( 9 ) of the electric motor unit ( 4 ), and a first safety device comprising at least one retractably mounted stop ( 17 ) and adapted to permit the coupling of the rotatable tool ( 13 ) with the output shaft ( 5 ) following retraction of said stop ( 17 ), only when the removable bowl ( 7 ) is correctly fixed on the base ( 9 ) and said base ( 9 ) is correctly seated in the reception seat ( 3 ), 
       characterized in that the stop ( 17 ) is retractably mounted in the reception seat ( 3 ) between an inactive position in which the stop permits the seating of the base ( 9 ) on the reception seat ( 3 ) and in which the stop is retracted by an actuating means ( 22 ) secured to the base ( 23 ) of the bowl when said bowl ( 7 ) is correctly fixed to the base ( 9 ), and an active position in which the stop projects in the direction of the output shaft ( 5 ) and of which a portion ( 24 ) comes into engagement with at least one notch ( 25 ) formed in the sidewall ( 10 ) of the base ( 9 ) so as to prevent the coupling of the rotatable tool ( 13 ) with the output shaft ( 5 ) and in which the stop avoids the actuating means ( 22 ) when the bowl ( 7 ) is not present or incorrectly fixed on the base ( 9 ).  
     
     
       2. Kitchen appliance according to  claim 1 , 
       characterized in that the stop ( 17 ) is retractably mounted through an opening ( 28 ) provided in the internal side surface ( 29 ) of the reception seat ( 3 ) and comprises the portion ( 24 ) which projects from said opening ( 28 ) when the bowl ( 7 ) is not present or incorrectly fixed on the base ( 9 ).  
     
     
       3. Kitchen appliance according to  claim 2 , 
       characterized in that the securement of the bowl ( 7 ) on the base ( 9 ) is obtained by means of a bayonet locking device comprising on the lateral surface ( 40 ) of the base ( 23 ) of the bowl ( 7 ) a plurality of lugs ( 26 ,  27 ,  26 ′ and  27 ′) constituting the actuating means ( 22 ) and in that the sidewall ( 10 ) of the base ( 9 ) comprises, in an internal surface ( 10 ′) of the sidewall, recesses ( 30 ,  31 ,  32  and  33 ) in which, in the course of assembly of the bowl ( 7 ) on the base ( 9 ), are adapted to engage respectively four lugs ( 26 ,  27 ,  26 ′ and  27 ′) of the bowl ( 7 ), the internal surface of the sidewall further comprising openings ( 34  and  35 ) in which, at the end of assembly of the bowl ( 7 ) on the base ( 9 ), said lugs ( 26 ,  27 ,  26 ′ and  27 ′) will snap in and open on the external surface ( 10 ″) of the base ( 9 ) such that, during positioning of the bowl-base assembly on the reception seat ( 3 ), one of the lugs will face the stop ( 17 ).  
     
     
       4. Kitchen appliance according to  claim 3 , further comprising a second safety device, wherein when the bowl ( 7 ) is fixed by rotation on the base ( 9 ), the second safety device is adapted to prevent reverse rotation of the bowl ( 7 ) on the base ( 9 ) when the base ( 9 ), together with the bowl correctly mounted on the base, is correctly seated on the reception seat ( 3 ). 
     
     
       5. Kitchen appliance according to  claim 4 , 
       wherein the reception seat ( 3 ) comprises annular projections ( 41 ,  42 ,  43  and  44 ), the stop ( 17 ) being movably mounted in at least one of the annular projections, and  
       wherein the second safety device comprises a piece ( 50 ) forming an abutment provided on one of the annular projections ( 41 ,  42 ,  43  and  44 ), projecting in the direction of the output shaft ( 5 ) and through a gap ( 50 ) provided in the sidewall ( 10 ) of the base ( 9 ).  
     
     
       6. Kitchen appliance according to  claim 2 , 
       characterized in that the removable securement of the bowl ( 7 ) on the base ( 9 ) is obtained by means of a screwthreaded securement, the bowl ( 7 ) comprising for this purpose a helicoidal rib having a lower sector which constitutes the actuating means ( 16 ), the sidewall ( 10 ) of the base ( 9 ) comprising a helicoidal groove of a shape complementary to that of the rib, a lower portion of the sidewall having an opening which communicates with the external sidewall ( 10 ″) of the base ( 9 ) and through which opens the lower sector such that, during positioning of the bowl-base assembly on the reception seat ( 3 ), the lower sector will be facing the stop ( 17 ) to retract the stop.  
     
     
       7. Kitchen appliance according to  claim 1 , 
       characterized in that the actuating means ( 22 ) is provided on the side surface ( 40 ) of the base ( 23 ) of the bowl ( 7 ) and comprises a projecting portion ( 48 ) forming a ramp adapted to retract the portion ( 24 ) during positioning of the bowl-base assembly on the reception seat ( 3 ).  
     
     
       8. Kitchen appliance according to  claim 1 , 
       characterized in that the reception seat ( 3 ) comprises annular projections ( 41 ,  42 ,  43  and  44 ), the stop ( 17 ) being movably mounted in at least one of the annular projections ( 41 ,  42 ,  43  and  44 ).  
     
     
       9. Kitchen appliance according to  claim 8 , 
       characterized in that the projections being four in number ( 41 ,  42 ,  43  and  44 ), each annular projection ( 41 ,  42 ,  43  and  44 ) comprises a stop ( 17 ).  
     
     
       10. Kitchen appliance according to  claim 1 , 
       characterized in that the stop ( 17 ) is movably mounted against a resilient means which tends to return the stop to the stop's active position.